Field Behavior And Performance Of Complex Fluids

Complex fluids are generally produced by mixing several distinct components together. They sometimes possess mixed physical properties of their elements, but in many cases, the interaction between different elements can give rise to unusual optical or rheological properties of the system as a whole, reflecting the new structural organization of their elements. The response of complex fluids when subjected to external perturbations, such as electric or magnetic field, thermo-field, or stress field, is extremely complicated, yet there are some novel features.Electrorheological (ER) fluids are a kind of complex fluids that is a suspension of high dielectric constant particles dispersed in an insulating oil of low dielectric constant, which have reversible and adjustable rheological property under the applied electric field.Encapsulated electrophoretic ink is also a kind of complex fluids which contains millions of microcapsules suspended in a liquid medium. Microcapsules take either of two forms. One type contains pigment chips of two colors, typically black and white, in a fluid. The other type contains pigment chips of one color in a liquid dye of a contrasting color. In either case, applying a voltage across a microcapsule moves pigment chips of a particular type toward one of two transparent electrodes. If you view the micro-capsule from the position of one electrode, you see the pigment chips of one color; if your view is from the other direction, you see the dye or pigment chips of the other color. By this way, E-paper can display different images. The image can keep several weeks or years without electric field. The contrast of two color can be adjusted by electric field. E-ink is filled between two lays of plastic films, then forms e-paper.The activity of electrorheological (ER) fluids and E-ink induced by electrostatic field , which is produced by piezoelectric ceramic , was investigated in this dissertation. On this foundation, the following results have been completed.1. The numerical simulations show that the resonant peak of the self-adaptive damper minish more than 60% compared with the damper whose Electrostatic field built by piezoelectric ceramic did not charge up ER fluids, then which proves that Electrostatic field built by piezoelectric ceramic can drive ER.2. Prepare the self-adaptive damper which consists of piezoelectric ceramic and ER fluids. The experiment show that the resonant peak of the self-adaptive damperminish more than 30% compared with the damper whose Electrostatic field built by piezoelectric ceramic did not charge up ER fluids.3. Build the system of collecting the stress of ER fluids, which consists of amplifier A/D transform card and the executed program. After the system is demarcatted, its performance is as follows: the stress resolution is 99Pa; The range of measure is 24kPa; The static error is less than 2%;4. Prepare the piezoelectric pen. The voltage of electrostatic field produced by the pen is more than 100V, which can drive E-paper; The piezoelectric pen accords with the writting habit and it is helpful to the environment.